Except for special bolts, there are 15 types of general bolts with outer diameters ranging from M4 to M36, but most of them are M10 to M20. The nominal length of the screw is 12-95mm. There are about 250 different kinds of bolts for excavators and about 130 kinds of screws for gas-pressure excavators.

In the past, bolts and corresponding gaskets were managed independently, but later developed matching bolts are flange bolts composed of gaskets. Standard parts are processed using composite bolts, which can serially manage bolts and gaskets. This method reduces the part number, miniaturizes the gasket, and also avoids the problem of under-installed gaskets.

In order to avoid bolt corrosion and adhesion, the bolts must be surface treated. When hot-dip galvanizing screws, hexavalent chromium-based passivating agents were used in the past. After it was found that hexavalent chromium had a negative impact on human health, all use was stopped.